Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 13, 2023 at 07:20 UT.

Charts (* = updated daily) Data and archive
  Solar wind (*) Solar and geomagnetic data - last month (*)
  Electron fluence (*) Archived daily reports and monthly data since 2003.01 (February 4, 2023)
Solar cycle Solar cycles 23-25 (February 1, 2023) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (February 1, 2023) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (July 1, 2020) POES auroral activity level [October 2009 - December 2012]
  Comparison of cycles 21-25 (February 1, 2023) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (February 1, 2023) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (January 21, 2023) Cycle 25 spots (final update December 25, 2019)
  Solar cycles 24-25 transition using 365d smoothing Research: Solar Cycle 25 Started on November 17, 2019 with 365 Days Smoothing

Recent activity

The geomagnetic field was quiet on February 12. Solar wind speed at SOHO ranged between 385 and 488 km/sec. The high latitude magnetometer at Andenes recorded quiet to active levels.

Solar flux density measured at 20h UT on 2.8 GHz was 199.7 - decreasing 28.4 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 132.37). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 6.8). Three hour interval K indices: 22221122 (planetary), 12322222 (Boulder), 33222244 (Andenes).

The background x-ray flux was at the class C2 level (GOES 16).

At the time of counting spots (see image time), spots were observed in 18 active regions using 2K resolution (SN: 397) and in 13 active regions using 1K resolution (SN: 243) SDO/HMI images.

Region 13213 [N30W62] decayed slowly and was mostly quiet.
Region 13214 [N12W45] produced flares early in the day and was quiet after noon.
Region 13215 [N22W21] was quiet and stable.
Region 13216 [N25W07] was quiet and stable.
Region 13217 [S11E22] decayed significantly and barely has penumbra on positive polarity spots. There is still a chance of M class flares.
Region 13218 [N10E05] was quiet and stable.
Region 13219 [S07E14] decayed slowly and quietly.
Region 13220 [S13E38] developed slowly and was quiet.
Region 13221 [N16E35] developed slowly and quietly.
Region 13223 [N14E18] decayed slowly and quietly.
Region 13224 [N21E37] decayed early in the day, then gained small spots as new flux emerged.
New region 13225 [S21E09] emerged on February 11 and was numbered the next day by SWPC.

Spotted regions not observed (or interpreted differently) by SWPC:
S8260 [S15W19] decayed slowly and quietly.
S8264 [S10E42] decayed slowly and quietly.
S8272 [S23E27] developed slowly and quietly.
New region S8276 [N10E48] emerged before noon and gained many small spots before the end of the day. The region has polarity intermixing and could produce C and minor M class flares.
New region S8277 [S02E57] emerged with tiny spots.
New region S8278 [S00W01] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.7 00:04   13222 GOES16  
C3.6 00:12   13213 GOES16  
C7.2 02:00   13217 GOES16 simultaneous flare in AR 13213
C4.0 02:37   13214 GOES16  
C8.8 03:44   13214 GOES16  
C3.5 04:24   13213 GOES16  
C5.0 05:02   13222 GOES16 simultaneous flare in AR 13214
C9.0/1F 05:41   13217 GOES16 simultaneous flare in AR 13214
M3.1/1B 08:48   13217 GOES16  
M1.4 09:27   13217 GOES16  
C3.7 11:12   13222 GOES16  
C5.2 12:01 behind northwest limb S8258 GOES16  
C5.0 13:05   13217 GOES16  
M1.2 13:34   13222 GOES16  
C3.9 14:36   13222 GOES16 simultaneous flare in AR 13213
C5.5 15:09   13217 GOES16  
M1.0 15:38   13217 GOES16  
C6.1 17:24   13222 GOES16  
C5.6 20:06   13222 GOES16  
C2.9 22:17   S8276 GOES16  
C3.8 23:01   13222 GOES16  
C3.3 00:04   13213 GOES16  

Coronal mass ejections (CMEs)

February 10: A large filament eruption in the southwest quadrant peaked near 09h UT and produced a partial halo CME. Components of this CME could reach Earth on February 13-15.
February 11: An impressive filament eruption began at approximately 10:50 UT to the east of AR 13216. The main part of the CME produced was fast and not Earth directed, however, slower moving components of the CME developed into a full halo CME. Effects could reach Earth on February 14.
February 12: No obviously Earth directed CMEs were observed in available LASCO imagery.

Coronal holes

[Coronal hole history (since October 2002)]
[Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago]

A northern hemisphere coronal hole could be numbered in the next report, it will likely rotate across the central meridian on February 14.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is poor. Propagation on long distance northeast-southwest paths is poor.

Forecast

Quiet geomagnetic conditions are likely on February 13. A flanking impact from the February 10 CME is possible on February 13 or 14 and could cause unsettled to minor storm conditions. The February 11 CME could reach Earth on February 14 and cause unsettled to major storm conditions until February 16.

Coronal holes (1) Coronal mass ejection (2) M and X class flares (3)
     

1) Effects from a coronal hole could reach Earth within the next 5 days. When the high speed stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.

Green: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% probability.

Active solar regions


(Click on image for 2K resolution). 4K resolution. Compare to the previous day's image.
0.5K image

When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue is positive.

Data for all officially numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC, all other regions are numbered sequentially as they emerge using the STAR spot number. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers. SWPC data considered to be not sufficiently precise (location, area, classification) are colored red.

Active region SWPC date numbered
STAR detected
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlays
Comment
SWPC/
USAF
Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
13208 2023.02.01
2023.02.01
3     N08W92 0030 CAO      

real location: N15W89

SWPC repositioned spotless plage AR 13208 on February 9 to an emerging region further south, see AR S8258

13209 2023.02.01
2023.02.03
      N20W66           location: N20W63
S8238 2023.02.03       S22W50          
13213 2023.02.04
2023.02.06
25 26 19 N30W64 0480 FKI FAI beta-gamma

location: N30W62

13214 2023.02.05
2023.02.06
9 21 14 N12W46 0390 DKI EKI

beta-gamma

area: 0550

13215 2023.02.05
2023.02.06
  2   N22W24 0003   BXO

location: N22W21

13216 2023.02.05
2023.02.06
3 8 5 N25W07 0140 HAX CAO  
S8247 2023.02.05       S27W56            
S8250 2023.02.06       S25W21            
S8254 2023.02.07       N22W41            
13218 2023.02.07
2023.02.08
1 8 3 N11E05 0010 HRX CRO

location: N10E05

area: 0020

13217 2023.02.07
2023.02.08
19 33 19 S12E22 0400 DKI DHI beta-gamma

location: S11E22

13219 2023.02.08
2023.02.09
3 6 3 S07E13 0020 HRX CRO location: S07E14
S8259 2023.02.08       N18E21            
S8260 2023.02.08   5   S15W19 0008   BXO  
S8261 2023.02.08       S09W35            
13220 2023.02.09
2023.02.09
2 12 6 S15E37 0150 CSO CHO area: 0290

location: S13E38

13221 2023.02.09
2023.02.09
3 14 10 N15E34 0040 HAX DRO area: 0050

location: N16E35

S8264 2023.02.09   4   S10E32 0006   BXO  
13222 2023.02.10
2023.02.10
3     N30W92 0040 DAO     rotated out of view
13223 2023.02.10
2023.02.11
  5 1 N17E16 0007   AXX location: N19E18
13224 2023.02.11
2023.02.11
3 18 6 N22E35 0010 BXO BXO area: 0020
13225 2023.02.11
2023.02.12
3 15 9 S22E06 0020 CRO DRO area: 0060
S8269 2023.02.11       S23W27          
S8271 2023.02.11       S22W35          
S8272 2023.02.11   13 8 S24E27 0030   CRO  
S8273 2023.02.11       N27E46          
S8274 2023.02.11       N22E54          
S8275 2023.02.11       S04E01          
S8276 2023.02.12   24 13 N10E48 0090   DRI    
S8277 2023.02.12   2   S02E57 0003   BXO    
S8278 2023.02.12   1   S00W01 0001   AXX    
Total spot count: 77 217 116  
Sunspot number: 197 397 246  (total spot count + 10 * number of spotted regions)
Weighted SN: 141 275 174  (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10)
Relative sunspot number (Wolf number): 217 218 197  

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number (4) Average ap
(3)
Measured 1 AU
2014.02 170.3
(cycle peak)
166.3 146.1 (SC24 peak) 110.5 10.70
2014.04 143.9 144.8 112.5 116.4 (solar max) 7.88
2017.09 91.3 92.3 43.6 18.2 (-1.3) 18.22
(cycle peak)
2019.11 70.2 68.7 0.5 2.0 (-0.6)
(Solar minimum using 365d smoothing:
November 17, 2019)
4.19
2019.12 70.8 68.6 1.6 1.8 (-0.2)
(ISN 13 months smoothed
solar minimum)
3.22
2021.07 81.0 83.6 34.3 31.4 (+3.8) 5.51
2021.08 77.7 79.7 22.0 35.4 (+4.0) 6.19
2021.09 87.0 88.2 51.3 40.2 (+4.8) 6.33
2021.10 88.9 88.3 37.4 45.2 (+5.0) 7.38
2021.11 86.2 84.4 34.8 50.8 (+5.6) 9.83
2021.12 103.0 99.8 67.5 55.9 (+5.1) 6.40
2022.01 103.8 100.5 55.3 60.1 (+4.2) 8.92
2022.02 109.1 106.5 60.9 64.7 (+4.6) 10.46
2022.03 117.0 115.8 78.6 68.7 (+4.0) 10.20
2022.04 130.8 131.7 84.0 73.0 (+4.3) 11.79
2022.05 133.8 136.8 96.5 77.2 (+4.2) 7.48
2022.06 116.1 119.8 70.3 80.9 (+3.7) 8.20
2022.07 125.4 129.5 91.4 86.5 (+5.6) 9.51
2022.08 114.2 117.1 74.6 (92.4 projected, +5.9) 10.92
2022.09 135.1 136.5 96.0 (97.4 projected, +5.0) 12.18
2022.10 133.5 132.7 95.4 (100.5 projected, +3.1) 11.16
2022.11 123.4 120.7 77.6 (103.4 projected, +2.9) 9.33
2022.12 147.9 143.4 113.1 (108.2 projected, +4.8) 10.99
2023.01 182.4 176.6 143.6 (114.2 projected, +6.0) 8.7
2023.02 171.4 (1)   53.6 (2A) / 125.1 (2B) / 168.8 (2C) (119.2 projected, +5.0) (10.9)
2023.03       (122.3 projected, +3.1)  
2023.04       (127.7 projected, +5.4)  
2023.05       (133.5 projected, +5.8)  
2023.06       (136.8 projected, +3.3)  
2023.07       (136.3 projected, -0.5)  
2023.11       (142.5 projected max SC25)  

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz and any corrections applied to that measurement.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days).
2B) Boulder SN current month average to date.
2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red are based on the definitive international GFZ Potsdam WDC ap indices.
4) Source: SIDC-SILSO.

Solar cycles 24-25

Smoothed SF and sunspot numbers

 

This report has been prepared by Jan Alvestad. It is based on the analysis of data from whatever sources are available at the time the report is prepared. All time references are to Universal Time. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.